The creator and star of HBO's hit Girls reportedly has scored at least $3.5 million to pen Not That Kind of Girl: A Young Woman Tells You What She's Learned, a nonfiction comedy book, via Random House.

Fey's own book of essays, Bossypants, has sold more than 1 million copies in the United States as well as 150,000 audio copies.

It's pretty clear that Random House is hoping to recreate the success of Bossypants, perhaps for a slightly younger demographic.

"I can see a strong argument for this level of advance," literary agent Celeste Fine of Sterling Lord tells me. And she offers this math:

Let's conservatively figure the publisher is making $4 to $6 a book (because it will). Random House would need to sell about 500,000 to a million copies to then break even.

Now, for its first and only season thus far, Dunham's show has logged a gross audience of more than 4 million.

Starting to get the picture?

"And awkward, smart girls like to buy books," Fine says. "So this is an aggressive investment, but not insane. Obviously there is always more risk at this level, but if they really get behind the book, they should be able to make it work."

Of course, the format of the book is also not an accident. This is not a novel; it's not a memoir. It's short, easy-to-digest anecdotes, and that's also important for sales, says Jason Boog of the publishing industry blog Galleycat.

"If you look at Tina Fey's book," he notes, "it was very easy to read. There was one section, 'A Mother's Prayer For Her Daughter,' that you could practically pull out of the book. People were emailing it to each other.

"Dunham's book also looks like it's going to be a series of anecdotes, and Random House is likely hoping to duplicate that model."

Know what else is super easy to read and totally fun? This column. Just sayin'.